Reintroduce android.test.base for Android R apps targeting Android Q.

The change http://r.android.com/909093 to remove android.test.base
is currently only included for Android R builds. This means that
apps running on Android Q get android.test.base regardless of their
targetSdkVersion (including Q).

It is inconsistent to remove it for those same apps when running
on Android R. Therefore, this CL changes the conditional removal
code only remove android.test.base for apps targeting an SDK
version > Q.

Test: atest FrameworksCoreTests:android.content.pm.AndroidTestBaseUpdaterTest
Test: Manually checked that I was able to reproduce the issue before
      this CL but not afterwards
Fixes: 133396946

Change-Id: I2861035c51cbc1d843a3371828f7902bea83c7cc